This invention is directed to certain novel organomagnesium compounds and processes for making such compounds.
In recent years, certain magnesium alkyl alkoxides and magnesium dialkoxides have been found to possess utility as precursors for magnesium chloride support materials utilized in the preparation of Ziegler-Natta catalysts for alpha-olefin polymerization.
For example, ethylene has been polymerized at 80.degree. C. in hexane using a magnesium alcoholate-TiCL.sub.4 reaction product (MgCl.sub.2) and a trialkyaluminum as the catalyst system. (M. Bahadir, S. Lutze, W. Payer, P. Schneller, Ger. Offen. No. DE 3,120,186, Dec. 9, 1982 to Ruhrchemie.) In another application, solid magnesium diethoxide, suspended in carbon tetrachloride, is treated with ethyl benzoate and titanium tetrachloride, and the resulting solid product is used in combination with trialkylaluminum and p-methoxybenzoate as a catalyst to polymerize propylene (B. L. Goodall, A. vander Nat, and W. Sjardyn, U.S. Pat. No. 4,414,132, to Shell Oil Co.).
Certain magnesium alkyl alkoxides and dialkoxides have also been generated by reaction of complexed magnesium dialkyls, coated on an inert support material, with an alcohol. These supported magnesium alkoxides are then further reacted with HCl and/or titanium tetrachloride to give a supported magnesium chloride catalyst which can be dried and used to polymerize ethylene (R. Hoff, U.S. Pat. No. 4,402,861 and R. A. Dombro, U.S. Pat. No. 4,378,304 to Chemplex Co.; and M. Bahadir and W. Payer, Ger. Offen. No. DE 3223331, to Ruhrchemie).
Certain magnesium dialkoxides, soluble in hydrocarbon solvents, have known utility for the preparation of MgCl.sub.2 which forms a useful support for catalysts to polymerize alpha-olefins, as shown by Goodall (U.S. Pat. Nos. 4,216,383; 4,426,316; and 4,387,200).
D. Gessell (U.S. Pat. Nos. 4,246,383; 4,426,316; and 4,244,838, to Dow Chemical Company) also describes the preparation of a useful alpha-olefin polymerization catalyst by reacting a dialkylmagnesium compound (in the presence of at least 50 mole % of a trialkylaluminum compound) with sufficient n-propyl alcohol to convert all of the alkyl groups to n-propoxy groups, thus forming a hydrocarbon-soluble solution of magnesium and aluminum n-propoxides, followed by reaction of the resulting solution with a titanium ester and a chlorinating agent, ethylaluminum dichloride, to give an MgCl.sub.2 -supported titanium catalyst.
It is also known to employ a mixture of certain dialkylmagnesiums and either lithium alkoxide, sodium alkoxide or potassium alkoxide in the polymerization and telomerization of butadiene to form low molecular weight liquid polymers, useful in the coating and also in the impregnation and encapsulation of electrical transformers and other metal parts to protect them from corrosion (C. W. Kamienski and J. F. Eastham, U.S. Pat. Nos. 3,742,077; 3,822,219; and 3,847,833). Other patents describing the formation of polymeric products from similar catalyst systems are U.S. Pat. Nos. 4,139,490 and 4,429,090 (to Firestone Tire & Rubber Co.), and U.S. Pat. No. 3,716,495 (to Phillips Petroleum Co.).
A known interchange of alkoxy and alkyl groups occurs on mixing these reagents to yield, in essence, a lithium, sodium or potassium alkyl and a magnesium alkoxide, as shown below: EQU 2(CH.sub.3).sub.3 CONa(K)+(n-C.sub.4 H.sub.9).sub.2 Mg.fwdarw.2n-C.sub.4 H.sub.9 Na(K)+[(CH.sub.3).sub.3 CO.sub.2 Mg
In still another application, a mixture of magnesium isopropoxides and aluminum isopropoxides in tetrahydrofuran (the solubility, if any, unspecified) is reacted with a solution of magnesium aluminum hydride in tetrahydrofuran (THF) to give a solution of magnesium aluminum isopropoxy hydride in THF. (S. Cucinella and G. Dozzi, Ger. Offen. No. DE 3000490, July 31, 1980, to Anic, Sp.A.).
It has, further, been known to the art, as disclosed in U.S. Pat. No. 4,375,564, to dissolve catalytic amounts of magnesium diethoxide and aluminum isopropoxide in a mixture of primary C.sub.12 -C.sub.13 alcohols, said resulting alcohol mixtures then being ethoxylated with ethylene oxide at a temperature of about 170.degree. C. to form alkanol alkoxylates, which are stated as being useful as non-ionic surfactants in detergent formulations.
Although certain magnesium alkyl alkoxides are known to be soluble in hydrocarbon solvents, as described in U.S. Pat. Nos. 4,410,742 and 4,133,824, and by G. E. Coates, J. A. Heslop, M. E. Redwood and D. Ridley, J. Chem. Soc., 1964, 2483 (see also B. J. Wakefield in Advances in Inorganic Chemistry and Radiochemistry, Vol. ii, 1968, p. 396 (Academic Press), little is known about the solubility of magnesium dialkoxides. It is known that both magnesium methoxide and ethoxide are insoluble in ethers and hydrocarbon solvents, as described in Kirk Othmer's Encyclopedia of Chemical Technology, Vol. 2, p. 12, 3rd Edition, John Wiley, 1978. Magnesium isopropoxide was found by D. Bryce-Smith and B. J. Wakefield (see above) to be insoluble in methylcyclohexane, benzene and ether, and only sparingly soluble in isopropanol. Magnesium t-butoxide is not soluble in ethyl ether (see Coates reference, as well as D. C. Bradley in Advances in Inorganic Chemistry and Radiochemistry, Vol. 15, 1972, p. 265 (Academic Press), and, thus, presumably, would be even less soluble in hydrocarbons. Solubility of magnesium alkoxides is not improved by the addition of aluminum alkyls (B. V. Johnson, N. M. Karayannis (EPA No. 95,290, to Standard Oil Company). From the dearth of information on magnesium dialkoxides, it would appear that these materials are, as a class, generally insoluble and intractable in most organic solvents.
C. G. Screttas (U.S. Pat. No. 3,932,545) describes, among other things, the preparation of magnesium 2-ethoxyethoxide in an excess of 2-ethoxyethanol; and, further, its use in dry form as an additive to promote the hydrocarbon solubility of arylmetallics such as phenylsodium, but does not teach its preparation and solubility in hydrocarbon solvents without such additives. (See, also, article in Organometallics, Vol. 3, 904-907, 1984).
Schell (U.S. Pat. No. 4,419,269) claims treating R.sub.2 Mg.xMR'.sub.x with alcohols of the general type R(OR').sub.n OH and Z(OR').sub.n OR").sub.n' in the presence of AL(R.sup.3).sub.3 mX.sub.m, but gives no examples of the use of 2-ethoxyethanol, and also not in the absence of aluminum compounds.
Esnault (U.S. Pat. No. 4,434,282) describes the reaction of DBM with certain diols, e.g., 2-methyl-2,4-pentanediol, 1,8-octanediol and 1,6-hexanediol, but intimates that, in the absence of aluminum alkyls, a "lumpy" product is formed.
Edwards (U.S. Pat. 4,375,564) describes the use of aluminum alkoxides in small quantity (10 mole %) to aid in the solution of magnesium alkoxides in C.sub.8 -C.sub.18 alkanols which are used as catalysts to promote the ethoxylation of these alkanols by ethylene oxide.
Aoki et al (U.S. Pat. No. 3,494,896) describe the curing of a mixture of a prepolymer of polyurethane with magnesium propylene glycolate (Mg(OCH.sub.2 CH.sub.2 CH.sub.2 OH).sub.2) as a catalyst to produce an improved sealant, but does not describe the preparation of the magnesium alkoxide nor its state (soluble or not) in the polyurethane composition.
British Pat. No. 870,418 describes the polymerization of monoepoxides in the presence of an aluminum or magnesium alkyl or alkoxide as catalyst.
Magnesium alkoxides of ethylene glycol and 1,2-propanediol are prepared in benzene by reaction with magnesium methoxide, but the resulting product is insoluble (P. Maleki, Ann. Chem., 1977, V. 2, p. 167-175).
It has now been discovered that, under certain conditions, certain magnesium dialkoxides can be prepared directly in liquid hydrocarbon or chlorinated hydrocarbon solvents, and possess a relatively high solubility therein.
Thus, it is one object of my invention to make available magnesium dialkoxides possessing a particularly high solubility in liquid hydrocarbon or chlorinated hydrocarbon solvents, and in the liquid hydrocarbon and chlorinated hydrocarbon solvent solutions thereof.
It is another object of my invention to provide a simplified process for the preparation of such magnesium alkoxides directly in the liquid hydrocarbon or chlorinated hydrocarbon solvents.
Another object of my invention is to prepare liquid hydrocarbon or chlorinated hydrocarbon-soluble stable complexes of magnesium dialkoxides with other metallic alkoxides, such as those of aluminum, boron, zinc, lithium, sodium, potassium, calcium, and barium.
A still further object of my invention is to provide a process for the preparation of liquid hydrocarbon or chlorinated hydrocarbon-soluble stable complexes of these magnesium dialkoxides with alkyllithium, alkylsodium, alkylpotassium, dialkylmagnesium and trialkyaluminum compounds and mixtures thereof.